Christopher Columbus left home in Genoa, Italy, as a teenager to become a sailor on the Mediterranean Sea. In the late 1470s he settled in Lisbon, Portugal, where he worked closely with master navigators and adopted the then-radical idea that land—specifically Asia—could be found by sailing west. (At the time, many Europeans believed that a ship sailing west would eventually drop off the edge of the world.) It took Columbus years to find sponsors for such a westward journey; finally, on August 3, 1492, he sailed for Spain with three ships: the Santa Maria (which he commanded), the Pinta, and the Nina.

After a stopover in the Canary Islands, Columbus sailed west from September 6 to October 7, and then southwest. Because the length and risk of the voyage alarmed the crew, Columbus kept secret his own log of distance traveled, and created a false log for the crew that indicated a lesser (and therefore less frightening) distance from Europe. Nevertheless, mutiny nearly occurred on October 10, just two days before reaching land in the Bahamas. After visiting numerous islands of the West Indies, Columbus returned to Portugal in January 1493, and on March 15 received a hero’s welcome in Spain.

On Columbus’s second voyage (1493–1496), he sailed for the West Indies with seventeen ships to establish colonies for Spain. But within months of the colonists’ arrival in Hispaniola—considered the most promising site—tens of thousands of natives had died from European diseases, forced labor, and murder at the hands of the Spanish.

On his third voyage (1498–1500), Columbus explored Trinidad and some of the South American mainland, and learned that conditions in Hispaniola had grown worse. When reports of Hispaniola reached Spain, Spanish officials were sent to arrest Columbus and bring him back in chains. Columbus was permitted to make a fourth voyage (1502–1504), but after landing in Honduras, he was stranded on Jamaica for a year and had to be rescued by the Spanish. He died two years later, still believing that he had reached Asia. Columbus’s explorations changed the course of western history. As a result, he remains a controversial figure. While some admire his bravery and consider him a hero, others condemn his role in the colonization of the Americas and the genocide of native peoples.